Lanxivi 30 PCS Gel Pen Refill 0.5mm Black Ink Replacement for, Zennyth and Kaco Retractable Gel ink Pen Rollerball Pen

works well, and for those wondering these fit my MR PEN black gel pen from the Selah collection. Took me awhile to find a pen refill that actually fit that brand.

The first one I tried bleed ink all over the page. I got one to write, but It did not write consistently, skipping and blotting. It felt like I was scratching the page, rather then writing smoothly. I do not recommend. This refill also has a smaller ink reservoir then other refills, which means you get less ink.

Really disappointed. Some of the refills work great, super smooth ink. But I'd say 60-70% of them - the ink is so stuck I have to throw them away - even after shaking the pen + refill as much as I could, even going as far as to heating up the ink with a blow dryer to try to make it run better. The ink often just doesn't write at all, or the ink barely flows even with a ton of force.

They write but often skip ink a lot Tested it a few different Ink pens

They didn’t fit in what I bought them for and the ink skips a lot.